Configurations and method of integrating a gas to liquids (GTL) plant in a refinery

Abstract

A crude oil processing plant that comprises a Fischer-Tropsch reactor is disclosed. The crude oil processing plant comprises a crude oil processing section and a hydrogen production section. The hydrogen production section is coupled to a hydrocracker in the crude oil processing section to deliver a high purity hydrogen stream. The Fischer-Tropsch reactor receives a syngas stream from the hydrogen production section and produces a hydrocarbon stream. When light crude oil is processed, the hydrocracker typically has excess capacities to upgrade the hydrocarbon stream from the Fischer-Tropsch reactor.

Description

[0001]This application claims priority to U.S. Provisional Application Ser. No. 62 / 030,000, filed Jul. 28, 2014. All extrinsic materials identified herein are incorporated by reference in their entirety.FIELD OF THE INVENTION[0002]The field of the invention is the integration of gas-to-liquids (“GTL”) processing within a refinery plant or crude oil processing plant, especially as it relates to plants that are designed to process heavy crude oils.BACKGROUND[0003]The background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.[0004]Many refinery plants or crude oil processing plants are designed to use heavy crude oil as feedstock to produce various valuable products. While there are benefits in processing heavy crude oils, the low cost of lig...

AI Technical Summary

Benefits of technology

[0007]The inventive subject matter provides apparatus, systems, and methods in which a crude oil processing plant can be more efficiently operated by utilizing a Fischer-Tropsch reactor. For example, a GTL plant can be integrated within an existing crude oil processing plant (e.g., a refinery) to make use of excess capacities, such as excess syngas and excess hydrocracking capacity. These excess capacities can be created when processing light crude oil in a crude oil processing plant that is designed for heavy crude oil. As used herein, the term “heavy crude oil” means any crude oil having an API gravity below 22.3° API (greater than 920 kg / m3), and the term “light crude oil” means any crude oil having an API gravity higher than 31.1° API (less than 870 kg / m3). In addition, high hydrogen crude oil can create excess capacities as described herein when processed in a crude oil processing plant that is designed for heavy crude oil. Thus, it should be appreciated that capital costs can be reduced by utilizing excess capacity from a crude oil processing plant.

[0010]It should be appreciated that the cetane number of a diesel product in the crude oil processing plant can be increased from 40 to at least 45 by feeding the hydrocarbon stream containing Fischer-Tropsch wax to the hydrocracker, which makes use of the excess hydrocracking capacity when processing a light crude oil instead of a heavy crude oil. Thus, the hydrocarbon stream can produce a cetane number when hydrocracked, such that it acts as a cetane booster when combined with the lower cetane product derived from the fractionated crude oil.

[0012]The crude oil processing plant can further comprise a saturator that is configured to receive a water stream from the Fischer-Tropsch reactor, a carbon dioxide stream from the hydrogen plant CO2 removal unit, and a first portion of a feed gas to produce a mixed gas stream. In contemplated embodiments, the feed gas is at least one of a natural gas stream and a refinery gas stream. Contemplated carbon dioxide removal units include an amine absorption unit, hot potassium, carbonate scrubbing, and other suitable acid gas removal process. The steam methane reformer can receive the mixed stream and a second portion of the feed gas to produce the steam methane reformer product stream which could be a syngas for feed to a Fischer Tropsch reaction unit. It should be appreciated that the saturator reduces the steam requirement for the steam methane reformer by generating at least some steam required for steam methane reforming from the Fischer-Tropsch water stream. Additionally, the saturator also acts to recycle and destroy light oxygenates that are formed in the Fischer-Tropsch reactor.

[0015]In contemplated embodiments, a mixture of naphtha, jet fuel, and a diesel product is generated via the hydrocracker, wherein the hydrocracker receives the hydrocarbon stream, the high purity hydrogen stream, and a fractionated crude oil from the distillation unit. It should be appreciated that feeding the hydrocarbon stream to the hydrocracker provides a Fischer-Tropsch wax to the hydrocracker in an amount effective to enhance a cetane number of the diesel product.

Problems solved by technology

Unfortunately, the availability of these low-cost feedstocks has created a mismatch with existing plant design.

Consequently, the cost of a standalone GTL plant can be relatively high, and can be especially troublesome for small scale plants in terms of the cost per barrel per day.

Images